[LEAPSECS] Leap second relationship to ISO 8601

[Clive D.W. Feather]

Brooks Harris said:
> In particular, 8601 implies use of "offset 
> from UTC", as indication of "local time", but conflates this with 
> Daylight Savings.

No, it doesn't.

It uses offset from UTC as an indication of, wait for it, offset from UTC.

> For example, a date and time in New York City might be 
> represented as 2014-07-04T00:00:00-05:00 which misses the fact that 
> Daylight was in effect, or 2014-07-04T00:00:00-04:00 which misses the 
> fact the the fixed timezone offset is -05:00.

No.

2014-07-04T00:00:00-05:00 means the start of the day according to a clock
observing an offset of -5 hours. Someone in New York City might have such a
clock if they needed to correspond with Chicago.

2014-07-04T00:00:00-04:00 means the start of the day according to a clock
observing an offset of -5 hours. That is the offset typically observed [1]
in New York City on that date.

The use of an offset does *NOT* imply either a time zone or the presence or
absence of an bi-annual shift.

My office in Cambridge has clocks on the wall showing the time in offsets
-07:00, -04:00, +01:00, +02:00, +05:30, and +08:00, because those are the
ones we regularly communicate. Though they all show different numbers, they
are all showing the same time.

[1] But see R.v Haddock [1967] BBC 1.4.

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Clive D.W. Feather          | If you lie to the compiler,
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